With the many thousands of MLM companies out there with a few dozen launching every day plus the massive competition for team members, no I wouldn't. I see MLM as a way to earn an extra income, however I believe that unless you're the owner of the company, or a relative of the owner that received a top position before the company was even announced, or a BIG marketer with a HUGE following... then you automatically start off at a disadvantage.
For retirement - I recommend people put the most (percentage) into your 401k that you can afford (you have to have money in there to make money). If your company does not provide a 401k, then have some of your regular pay automatically taken out before (or right after) you receive it and have it deposited into a Roth account.
Note: I have nothing against MLM as I'm directly involved in a few MLM companies, however I view the income from those as "extra income" not something for retirement. When I retire and with attrition as a natural part of MLM, I wouldn't want to be retired yet still keep marketing to ensure my MLM retirement income continued at a reliable level.
A very interesting question, thanks!